Display system and method for registration control equipment

ABSTRACT

A display system is disclosed which operates its repetitive horizontal deflection as a function of encoder pulses keyed to web movement (rather than time), and which displays scanner signals as vertical deflection. For accurate viewing, the full horizontal deflection can take place while scanning a fraction of the repeat length of the web. In order to select marks for registration control, the portion of a repeat length to be displayed can be continuously changed until potentially suitable marks appear on the display, whereupon such marks can be checked for stability, and spurious signals can be excluded from the inspection zone, since horizontal deflection is precisely locked to the desired portion of the repeat length and is synchronized with the inspection zone of the registration control. A master unit including the display apparatus can be selectively coupled with a number of different work stations in succession and can selectively display outputs of one or both of a pair of scanners at each station.

United States Patent Coberley et al.

[54] DISPLAY SYSTEM AND METHOD FOR REGISTRATION CONTROL EQUIPMENT [75]Inventors: Daniel A. Coberley, Danville; Mark Resh, Urbana, both of Ill.

[73] Assignee: Hurletron Altair, Danville, ll].

[22] Filed: May 28, 1974 [21] Appl. No.: 473,707

[52] US. Cl 235/92 MP; 235/92 DN; 235/92 V; 235/92 R; 340/259 [51] Int.Cl. 606M 3/02 [58] Field of Search........ 235/92 MP, 92 V, 92 CV,235/92 DN; 250/563, 561, 559, 571; 340/259, 324 A [56] References CitedUNITED STATES PATENTS 3,812,351 5/1974 Coberley 235/92 MP PrimaryExaminerJoseph M. Thesz, Jr. Attorney, Agent, or FirmHill, Gross,Simpson, Van Santen, Steadman, Chiara & Simpson [57] ABSTRACT A displaysystem is disclosed which operates its repetitive horizontal deflectionas a function of encoder pulses keyed to web movement (rather thantime), and which displays scanner signals as vertical deflection. Foraccurate viewing, the full horizontal deflection can take place whilescanning a fraction of the repeat length of the web. In order to selectmarks for registration control, the portion of a repeat length to bedisplayed can be continuously changed until potentially suitable marksappear on the display, whereupon such marks can be checked forstability, and spurious signals can be excluded from the inspectionzone, since horizontal deflection is precisely locked to the desiredportion of the repeat length and is synchronized with the inspectionzone of the registration control. A master unit including the displayapparatus can be selectively coupled with a number of different workstations in succession and can selectively display outputs of one orboth of a pair of scanners at each station.

6 Claims, 18 Drawing Figures U.S. Patent Oct. 21, 1975 Sheet10f73,914,582

Sheet 2 of 7 Patent Oct. 21, 1975 US. Patent Oct. 21, 1975 Sheet30f73,914,582

NXQQN Sheet 6 of 7 US. Patent 0a. 21, 1975 DISPLAY SYSTEM AND METHOD FORREGISTRATION CONTROL EQUIPMENT BACKGROUND OF THE INVENTION In setting upregistration control systems, it is essential to select marks forcontrol purposes which occur reliably in the successive repeat lengthsof the web and to exclude spurious marks from the inspection zone of thecontrol. Longitudinal or lateral control of the web relative to a workstation can be effected by selecting a suitable pair of marks andproducing pulses as a function thereof during scanning of each repeatlength of the web. Typically once suitable marks have been selected, thesystem is adjusted to that the pulses will occur in time coincidencewhen the web is in proper longitudinal or lateral register condition.Phase errors between such pulses can be used to generate error signals,and the web can be acted upon in response to such error signals to tendto maintain the desired register condition. Such controls may includeblanking circuitry such that only pulses occurring during a fractionalpart of each cycle of operation will be processed for control purpose.The time interval in each cycle of operation when scanner pulses areaccepted may be termed an inspection zone, and the system may bevisualized as having an inspection window of limited extent throughwhich a given section of the repeat length of the web will be viewed ineach cycle of operation. By the provision of such an inspection window,and proper selection of the marks to be used for control purposes,spurious signals due to extraneous markings on the web can be excludedso as to insure a reliable operation of the registration control.

SUMMARY OF THE INVENTION:

The present invention relates to a display system and method for usewith registration controls, and to a registration sensing system.

It is a principal object of the invention to provide a display systemand method for displaying scanner signals during set-up of aregistration control which display system provides for a high resolutiondisplay of a fraction of a repeat length of the web, but yet enables aconvenient and simple progressive examination of the entire repeatlength and a reliable locking onto a potential inspection zone, with theresult that unstable or spurious scanner signals are readily discoveredand excluded from the inspection window.

Another object of the invention is to provide a master display unit fora registration control which can be readily coupled to a series of workstations in succes sion during a set-up operation and wherein theoutputs of one or both of a pair of scanners at each station are readilydisplayed.

A feature of the invention resides in the provision of a single multitumcontinuous adjustment knob for manual turning to progressively examinesuccessive potential inspection zones relative to the repeat length of amoving web. When rotation of the knob is interrupted the display islocked to the web so as to provide an apprently stationary view of thesignals occurring during a potential inspection zone, that is a viewthrough the inspection window. The cycling of a scan gate counter can besynchronized with the horizontal deflection of the display so that theinspection window of the register control will be accurately displayedfor each setting of the adjustment knob.

A further object of the invention is to provide a register error sensingsystem for progressively adjusting the set point of the system in aconvenient and economical manner.

A further feature of the invention resides in the provision of acontinuously operable analog setting control for selectively setting anyof a series of analog values of an analog characteristic within a givenrange, a cyclically operable pulse responsive generator generating ananalog signal successively changing in the analog characteristicsthereof over the given range, and the set point for the register errorsensing circuit bearing a fixed relationship to the instant of time whena matching relationship is established between the selected analogsetting and the generator output in each generating cycle.

Further objects, features and advantages of the invention will bereadily apparent from the following detailed description taken inconnection with the accompanying drawings, althrough variations andmodifications may be effected without departing from the spirit andscope of the novel concepts of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS:

FIG. 1 is a diagrammatic illustration of an embodiment of the presentinvention, given by way of example and not by way of limitation;

FIG. 1A is a waveform diagram illustrating an exemplary pulse outputfrom the index generator of FIG. 1;

FIG. 1B is a waveform diagram illustrating an analog signal successivelychanging in an analog characteristic thereof in successive generatingcycles of a pulse responsive generator, specifically illustrated as arepeat length ramp generator in FIG. 1;

FIG. 1C illustrates an analog variable whose analog value with respectto the analog characteristic of the waveform of FIG. 1B is progressivelyadjustable within the range of values illustrated in FIG. 18;

FIG. 1D illustrates the output of the analog selector circuitspecifically shown as a channel amplitude selector in FIG. 1 independence on the amplitude setting as represented in FIG. 1C;

FIG. 1E shows scanner pulses as applied by one of the channel scannerpreamplifiers of FIG. 1, the horizontal axis in FIG. 1B being in termsof encoder pulses the same as FIGS. 1A throught 1D;

FIG. 1F is a view similar to FIG. 1E, showing the output of the otherchannel scanner preamplifier of FIG.

FIG. 1G is a waveform diagram intended to be on the same horizontalscale as FIGS. 1A through 1F, and showing a display referencedisplacement signal, specifically a horizontal deflection signal fromthe horizontal deflection circuits component of FIG. 1, in successivecycles of the cyclically operable reference displacement generator,specifically implemented as a cyclically operable horizontal deflectioncounter converter in FIG. 1;

FIG. 2 is a diagrammatic illustration of a display as produced pursuantto the operation as illustrated in FIGS. 1A through 1G, the horizontalaxis in FIG. 2 representing the display reference displacement axis, andthe vertical axis in FIG. 2 representing the signal display axis withrespect to the display apparatus of FIG.

FIG. 3 is a schematic electric circuit diagram illustrating a portion ofa specific embodiment in accordance with the block diagram of FIG. 1;

FIG. 4 is a diagrammatic view illustrating the physical relationshipbetween FIGS. 5 and 7-10, which taken together illustrate furtherportions of the electric circult;

FIG. 5 illustrates exemplary electric circuitry for implementing thechannel amplitude selector component of FIG. 1 in particular, as well ascertain circuitry in accordance with the diagram of FIG. 1;

FIG. 6 illustrates circuitry which is coupled with the scope triggeroutput of FIG. 5 and which interconnected with the circuitry of FIG. 3and FIG. 7 at the points indicated;

FIG. 7 illustrates certain of the scanner processing circuitry of thechannel scanner processing and registration error sensing circuitry ofFIG. 1;

FIG. 8 illustrates certain of the registration error sensing circuitryof the channel scanner processing and registration error sensingcircuitry component of FIG. 1;

FIG. 9 illustrates further circuitry including a scan gate counter andan error counter of the channel 'scanner processing and registrationerror sensing circuitry of FIG. 1, and also illustrates certain detailsof the circuitry of the channel digital error display component of FIG.1;

FIG. 10 on sheet 5 of the drawings illustrates an exemplary outputdriving circuit which is controlled by means of relay coilsdiagrammatically indicated at the upper right in FIG. 8; and FIG. 10A onsheet 5 of the drawings is an exemplary detailed view of a typicalembodiment of the bidirectional output servo component of FIG. 10 andshowing the coupling of the output motor with an error correction devicefor the moving web, an edge view of the web being shown in FIG. 10A, anda diagrammatic fragmentary plan view of the web being shown in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS:

The block diagram of FIG. 1 shows components of the illustratedembodiment which are labeled so as to conform with the correspondingcomponents of the detailed electric circuit of FIGS. 3 through 10. Thus,FIG. 1 is presented for the purpose of facilitating an understanding ofthe detailed embodiment, and is shown by way of illustration and not byway of limitation.

Description of FIG. 1

The present invention is particularly adapted for use with registrationerror sensing circuitry such as employed for the purpose of sensing alongitudinal or lateral registration condition between a moving web suchas indicated at 10 and a work applying station such as work applyingstation B indicated diagrammatically at 11. Prior patents such as U.S.Pat. No. 3,468,201 issued Sept. 23, 1969, U.S. Pat. No. 3,594,552 issuedJuly 20, 1971, U.S. Pat. Nos. 3,601,587 and 3,624,359 will illustratethe background with reference to typical longitudinal register controlsystems. Entirely similar circuitry is applicable with respect to theproblem of control of the lateral position of the web relative to a workapplying station or the like.

In the illustrated embodiment, web 10 is shown as being driven in thedirection of arrow 12 by means of eration at'the work applying stationB, for example.-

a suitable web drive 14. It may be assumed that at a work applyingstation A (not shown) marks such as indicated at Al-l through A1-6 andsuch as A2-l through A2-6 are applied to successive repeat lengths onthe web along with patterns of work such as diagrammatically indicatedat 15.

By 'way of example, at work applying station B, it may be desired tosuperimpose on the pattern of work 15 a further pattern of work so as toprovide a resultant pattern of work as indicated at 17, the workapplying station B being indicated as applying also marks Bl-l throughB14 and 82-] through B2-3 (the mark B2-4, not shoyvn, being visualizedas being currently applied to'the web at the work applying station B).

For the sake of maintaining a longitudinal register condition betweenthepatterns 15 applied at station A (not shown) and the further patternsapplied at station B to form the composite pattern such as indicated at17, scanners are arranged as indicated at 19 and 20 forphotoelectrically sensing the passage of the respective A and B marks inlongitudinal alignment therewith. The scanners 19 and 20 produceelectrical signals as a result of the contrasting light reflectiveproperties of the marks, and these signals are supplied to respectivechannel scanner preamplifiers as represented by block 21 in FIG. 1. Theoutput scanner pulses from the preamplifiers are diagrammaticallyindicated in FIGS. 1E and IF, the notation Al in FIG. 1E, for example,indicating a pulse produced in response to scanning of one of the markssuch as Al-l on the web 10. Similarly, FIG. 1F indicates the outputresulting from the sensing by scanner 20 of the different lightreflective properties of the marks such as indicated at 81-1 and 82-1.

For the sake of the diagrammatic showing of FIG. 1, it is assumed thatweb drive 14 is suitably driven by a prime mover (not shown), and thatthe mechanical movement of the drive element 14 is coupled with adigital encoder component 24 and an index generator 25 by means ofmechanical couplings as indicated at 26 and 28. For the sake of aspecific example, it may be assumed that digital encoder 24 is driven soas to make one complete revolution during the movement of a repeatlength of the web, the rotation of the digital encoder 24 beingessentially in synchronism with the movement of the web, and the digitalencoder providing apredetermined number of encoder pulses per revolutionsuch as 10,000 so that each encoder pulse represents a predetermineduniform increment of movement of the web 10. FIGS. 1A through 1G eachshows a horizontal axis measured in terms of encoder pulses, the number20,000 in FIGS. 1A and 1B representing 20,000 encoder pulses, or twocomplete revolutions of the digital encoder 24. As explained in U.S.Pat. No. 3,468,201 for example, a single pulse per revolution of thedigital encoder 24 may be generated by means of a device which is hereintermed an index generator and represented by component 25. The output ofthe index generator is indicated in FIG. 1A as a series of pulses 3l-33,one occurring for each 10,000 pulses (indicated by the symbol ENC). Theindex pulses of FIG. 1A thus represent electrically the successiverepeat lengths of the web 10, and serve to coordinate the cycles ofoperation of the electrical system with the mechanical movement of theweb 10. The successive index pulses 31-33 are also coordinated with thecyclical work op- The index generator is shown as applying its indexpulse output to a repeat length ramp generator component 36 so as toreset this component in preparation for a new cycle of operation. Asillustrated in FIG. 1B, the ramp generator 36 may respond to successiveencoder pulses to provide a progressively changing amplitude output asrepresented in FIG. 1B. The output of the ramp generator 36 may besuppled in parallel to a number of channels, each channel associatedwith one of the work applying stations, and a channel amplitude selectorcomponent 38 being indicated which is associated with the work applyingstation B. The channel amplitude selector 38 is provided withacontinuously rotatable knob 40 which in the illustrated embodiment isoperable to continuously adjust an amplitude level over a range such asindicated by the arrows 42 in FIG. 1C, corresponding to the range ofvariation of the analog output from generator component 36 asrepresented in FIG. 1B. The amplitude selector .38 provides a pulseoutput as indicated at..43 and 44 in FIG. ID at the instant of time whenthe amplitude setting of knob of 40 coincides with the analog outputfrom the ramp generator 36. Thus, the phase of the pulses 43 and 44 mayvary, as a function of encoder pulses as represented by arrows 45 and 46in dependence on the setting of the knob 40. r

. Referring to the terminology of US. Pat. No. 3,594,552, the outputpulse from the amplitude selector component 38 corresponds 'to an UNITZERO pulse and is herein termed an initiating signal. As will beunderstood from a considerationof US Pat. No. 3,594,552, andparticularly the tenthfig ure of this patent, the output signal fromselector38 may represent the start of an inspection zone or a scannergate interval, during which scanner pulses supply to the channel scannerprocessing and registration: error sensing circuitry 50 will beeffective in determining the registra tion condition with respect to agiven repeat length of the web. As will be understood in the art, theeffective scanner pulses may give rise to registration pulses within thecircuitry 50 which will be time coincident when a given repeat length ofthe web is in register with respect to the work station 11. Thecircuitry 50 receives encoder pulses from component 24 as indicated bycoupling line 52 and is operable to show the number of encoder pulsescorresponding to any registration error by means of the error displaycomponent 54.

' As previously discussed, in order to set up a registration errorsensing circuitry, it is unnecessary to select suitable marks on thewebwhich occur reliably in the successive repeat lengths, and aresufficiently clear of spurious signals so that they can be discriminatedby means of the inspectionzone or inspection window of the system. Intheillust-rated embodiment a cathode ray tube is indicated at 60 havinga display face..62 with a horizontal or reference displacement axis and:a vertical or signal display axis.

The illustrated circuitry provides for the initation of a displaycycle-offthe apparatus 60 in response to the initiating signal outputfrom component 38. In particular a selector switch S1 is shown as havinga position S1-4 whereby the switch is connectedwith the output of theselector component 38. In other positions of the selector S1, connectionis made with the output of correspondingamplitude selectors withrespectto other work stations (such as a work station C, notshown). Withthe selector S1 in the position shown, the output of selector 38 issupplied through a pulse shaper 64 so as to provide a cyclicallyoccurring display control pulse as represented in FIG. 1D and whoseoccurrence relative to web movement is progressively adjustable by meansof knob 40. The pulses of FIG. ID are shown as being supplied to abistable display control circuit indicated at 66 which serves toinitiate the successive display cycles by resetting an encoder pulserate divider 68 and a cyclically operable horizontal deflection counterconverter 70 in the specific illustrated embodiment. The component 70 isshown as having a switch 72 at its input for selectively supplyingencoder pulses directly thereto, or supplying pulses via the pulse ratedivider 68. With the switch 72 in the position shown, the displayapparatus 60 will essentially provide a full horizontal deflectioncorresponding to the inspection zone of the circuitry 50, and thisswitch position has accordingly been designated 11. In the alternativelower position of switch 72, full deflection of the display apparatus 60will take place during all revolution of encoder 24 and thus willcorrespond to a full repeat length on the web. The lower switch contacthas accordingly been designated (F.R.). FIG. 1G shows the output fromhorizontal deflection circuits component 74 with the switch 72 in theupper position. As indicated in FIG. 1G and FIG. 2, under thesecircumstances, the full deflection of the display apparatus 60 withrespect to the horizontal or reference axis will take place in responseto 500 encoder pulses as supplied from component 24. Thus, the pulsesappearing in FIG. 2 in solid outline, are intended to correspond to aninspection zone such as defined by the occurrence of display pulse 44 inFIG. 1D. FIG. 2 may be taken as indicating that the pulse A2 whichoccurs in response to marks such as A2-l and A2-2 during continuousmovement of the web, will not be displayed since it occurs outside ofthe 500 encoder pulse inspection zone which is actually shown at thedisplay face 62 of apparatus 60 in response to a display signal 44.

Component may conveniently comprise a counter for counting encoderpulses and for actuating gate 76 at such time as the counter has reacheda count of 500. Thus at the end of the 500 count interval indicated inFIG. 2, gate 76 will signal the display control circuits 66 and thuscause the termination of a display cycle prior to the occurence of thesignal as indicated at A2 in FIG. 1E and FIG. 2. The counter ofcomponent 70 may drive a digital to analog converter also a part ofcomponent 70 and the output of the digital to analog converter ofcomponent 70 may supply the input to the horizontal deflection circuits74 so as to provide the deflection signal as represented in FIG. 1G.

As further represented in FIG. 1, the scanner signals of FIGS. 1E and IFmay be selected by means of selector switches S2 and S3 which may beganged for joint operation with selector S1. Thus, selectors S2 and S3are shown as disposed at positions S2-4 and S3-4 so as to receive thescanner signals with reference to station B. These scanner signals aresupplied to a vertical deflection control input signal circuitscomponent 80 which in turn controls the vertical or signal display axisof apparatus 60 corresponding to the vertical axis in FIG. 2. Fordisplaying the outputs of both scanners l9 and 20 during an inspectionzone interval, the output of display'control circuit 66 may be coupledto the clock'input of a J K flip-flop 82, the outputs of the flipflopalternately enabling transmission of the A and B scanner signals, sothat a signal A1 is generated during one display cycle, and a signal B2is generated in the next display cycle, the two signals being in effectsuperimposed on the display face 62 where the display face 62 has asuitable persistence or other memory feature, properly related to thenormal operating speed range of the web 10. Thus if at a normal speed ofthe web, move-, ment would be at a rate of two repeat lengths persecond, then the display apparatus 60 should be capable of providing apersistent signal without substantial flicker where the signals occur atthe rate of one pulse per second. Of course, the persistence of thedisplay face 62 should not be such as to interfere with an accurateappraisal of the currently occurring scanner pulses.

Description of the Circuitry of FIGS. 3 A

Certain of the circuit detail of the illustrated circuit is similar inprinciple so that described in detail US. Pat. No. 3,812,351 issued May21, 1974, so that a less detailed description is suitable herein. Innumerous cases, as in the mentioned patent, reference characters areapplied which correspond to the last two digits of commercialdesignations for transistor transistor logic integrated circuits. Thus,for example, in FIG. 3 the ramp generator counter stages are givendesignations 93C, 93D and 93E, and suitable implementing circuitry wouldcomprise mediumscale integration four-bit binary counters commerciallyavailable as circuit types SN 7493. Similarly, the input JK flip-flopdesignated 73-1 could be implemented as a circuit type SN 7473. Thereference characters utilized in FIG. 1 have been repeated in FIGS. 3through 10 where applicable so as to further facilitate a review of thedetailed circuit. Also, reference characters in such as (1A) shown atthe left in FIG. 3 indicate that the waveform of the correspondingfigure number, i.e. FIG. 1A, would be supplied at the indicated circuitlocation.

In order to facilitate implementation of the specific illustratedcircuit, should be desired, specific circuit values have been indicatedfor the components of the detailed circuit. In this respect, thenotation K as applied to a resistor refers to a value of resistance inkilohms. Capacitance values are indicated by a decimal number are inmicrofarads in each case. Other values of capacitance are indicatedusing the notation pf, standing for microfarads or pf standing forpicofarads (10' farads). Resistance values or less than 1 kilohm (1K)are indicated with the conventional symbol for ohms(fl).

FIG. 3

Referring to FIG. 3, at the upper left, the input index pulses aresupplied to transistor Q303, driving a gate 00-1 (a circuit type SN7400, for example). The output of this circuit via conductor 101 servesto reset the stages of the ramp generator 36, whereupon it beginscounting encoder pulses as applied to input 102 at the left in FIG. 3. Adigital to analog converter 104 of component- 36 generates the rampoutput waveform of FIG. 113 at output conductor 105. A reset pulse issupplied to conductor 107 shown at the upper right in FIG. 3 fromcomponent 66, FIG. 1, and serves to reset pulse rate divider 68 (circuittype SN 7490, for example),

and counter stages 93A and 93B of horizontal deflection counter covertercomponent 70, shown at the lower right in FIG. 3. The component70'includes a digital to analog converter 110 for driving horizontaldeflection circuits 74 to produce the horizontal deflection waveform ofFIG. 16 at conductor 111 leading to one of the horizontal deflectionplates of cathode ray tube 60. When the counter stages 93A and 93B ofcomponent reach a count corresponding to the extent of the inspectionzone of circuitry 50, FIG. 1, gate component 76 (for example a type SN7430) will supply an output signal to its output line 112 leading toFIG. 6.

The vertical deflection signal from component 80, FIG. 1 is supplied tothe vertical deflection plates of cathode ray tube 60 via conductors 115and 116 which originate in FIG. 6.

The circuit associated with transistor Q305 at the upper left of FIG. 3controls circuitry in FIG. 6 via a conductor 120.

FIG. 5

Referring to FIG. 5, it will be observed that the waveform of FIG. 1B issupplied via line 105 to a minus input of a differential/operationalamplifier 741C (circuit type SN 72741, for example). The plus inputterminal of amplifier 741C is coupled with the movable contact 122 of apotentiometer 123 which is operated by the knob 40 and may beimplemented as a ten turn, 2,000 ohm potentiometer for controlling theanalog setting represented in FIG. 1C. Upon the matching of analogsignal levels at the two inputs of the amplifiers 741C, an output signaltermed Scope Trigger is supplied to conductor 125 leading to FIG. 6.

The output of amplitude selector 38 is also applied to a transistor0306-1, whose output triggers a monostable circuit 130. The output ofmonostable in turn drives a series of gates so as to produce outputpulses at conductors 131, 132 and 133.

The circuit at the lower part of FIG. 5 involving transistor Q3071 mayserve to double the encoder pulse rate so as to supply at outputconductor 135 pulses at a rate of 20,000 per revolution of encoder 24,for example.

The monostable multivibrator 130 may comprise a type SN 74121, forexample. The commercial data for this type of circuit indicates that foran applied voltage between five and 5.25 volts, pulse width is definedby the relationship p (out)=C R log 2. Jitter-free operation is said tobe maintained over the full temperature range for more than six decadesof timing capacitance (l0 pf to 10 pf) and more than one decade oftiming resistance (2,000 ohms to 40,000 ohms). Thus, thecircuit-parameters for R330 (16 kilohms) and C313 (22 microfarads) areassumed to give a time constant of roughly 255 milliseconds.

Since with this type of circuit, once the monostable has been triggered,the outputs are independent of further transitions on the input and area function only of the timing components, monostable 130 will inherentlyadaptably regulate the number of cycles which can be initiated by theScope Trigger, and is selected to reduce the number of error cycles ofthe error sensing circuitry at relatively high web speeds, whileaccommodating error correction operation for each 'repeat length of theweb at somewhat lower speeds.

" R330 with a value of 30,000 ohms, and a capacitor corresponding toC313 again of 22 microfarads.

The monostable 130 of FIG. is part of the registration error sensingcircuitry of component 50, and the connection between component 38 andthe monostable circuit is indicated by conductor 140 in FIG. 5 and byline 140 in FIG. 1.

FIG. 6

The Scope Trigger input 150 at the upper left in FIG. 6 corresponds toline 150 at the output of selector S1 in FIG. 1. The bistable 66 istriggered in response to the display control signals such as 43 and 44in FIG. 1D, and the output from gate 01-2A which is applied to conductor107 serves to reset the horizontal deflection counter convertercomponent 70, FIGS. 1 and 3. The output of gate 01-1A, at this time,will be effective to enable gates 00-1B and 00-2B, providing the go downcircuit associated with transistor 0305 at the top of FIG. 3 has notapplied a ground potential to conductor 120. That is, if the web speedis below a selected minimum, the corresponding encoder pulse rate willbe such as to enable charging of capacitor 152 at the top of FIG. 3,turning the transistor W305 at the top of FIG. 3 on, that is to theconducting condition, so as to apply ground potential to conductor 120.Thus at speeds of the web below the minimum speed, gates 00-18 and 00-2Bin FIG. 6 will be blocked, and output lines 155 and 156 will be atground potential to block transistor 0300 and 0302-1, thus preventingthe appearance of vertical deflection signals at output conductors 115and 116 at the right in FIG. 6 in response to scanner signals occuringduring the inspection zone. If the web speed is adequate for suitableoperation of the display apparatus 60, then gates 00-18 and 00-23 willbe enabled in response to the successive display control signals such as43 and 44 in FIG. 1B so as to enable display of selected scanner signalsduring the inspection zone.

As indicated in the top center of FIG. 6, a display control switch 160has three positions. In the indicated open circuit condition, scannersignals A1 and B2 are displayed in alternative cycles of the displayapparatus so as to provide a resultant composite display as indicated inFIG. 2. If selector 160 is placed in the second position designated Ch2in FIG. 6, then flip-flop 82 (which may be a circuit type SN 7473) isplaced in an actuated condition in response to the first occurring clockpulse, and thereafter continuously enables the lower scanner channelinvolving transistor 0302-1. Similarly, if selector 160 is in the lowerposition, flipflop 82 is locked in the opposite (reset) state to enabletransistor 0300.

Regardless of. the state of transistors 0300 and 0302-1, the scannersignals such as indicated at FIGS. 1E and IF are supplied via conductors171 and 172 to the error sensing circuitry of FIG. 7. A socket isindicated at 174 forreceiving a scope probe useful in trouble shootingthe circuitry and thelike. With a probe inserted in socket 174, signalsfrom the probe are substituted for the usual scanner signals from thescanners 19 and 20. I

FIG. 7

FIG. 7- illustrates channel scanner processing circuitry which formspart of component 50, FIG. 1, the pulse outputs at conductors 181 and182 being supplied to the circuitry of FIG. 8. It will be noted thatflipflops 74A-1 and 74A-2 at the right in FIG. 7 must be reset fromconductor 132 at the beginning of each inspection zone, or else theerror sensing circuitry will be unable to carry an sensing cycle. Thus,at relatively high web speed, where a monostable circuit 130, FIG. 5,fails to respond to alternate scope trigger pulses, for example, scannerpulses will also be blocked during alternate potential inspection zones.

FIG. 8

In FIG. 8, the scanner signals arrive via conductors 181 and 182 and areselectively routed by means of a three pole double throw switch 191controlled by means of a shiftable contact 192. The condition of theswitch 191 may be selected so that the leading scanner pulse, such aspulse A1 as seen in FIG. 2, will be transmitted to output 194 andthenceto the offset counter comprising stages C and 90D. The offset counter asindicated has thumb wheel switches as indicated at 195 and 196 forselecting a desired count value between zero and 99 with respect to thedouble rate encoder pulses supplied via conductor from FIG. 5.

When the offset counter has completed the desired counting cycle, anoutput is supplied from comparator stages 42A and 42B via conductor 197,and this pulse serves to reset bistable circuit 198 and supply a delayedscanner pulse to output 199 of the switch 191. Accordingly bistable 200will assume a final condition in accordance with any significant errorin phase between the two scanner pulses and supply a correspondingpolarity siganl to conductor 201 or conductor 202.

If polarity indicating conductor 201 is high, transistor 0507 will beenabled to allow energization of the relay coil designated REED 2. Onthe other hand, polarity indicating conductor 202 is high, thentransistor 0508 will be enabled to permit energization of the actuatingcoil designated REED 1.

During the counting of encoder pulses to determin the error between thesignals arriving at the respective inputs to flip-flop 200, thepotential at conductor 210 at the extreme right in FIG. 8 will be high,turning on transistor 0504-1 at the upper left in FIG. 8. This in turnwill turn on transistor 0505-1, and allow the discharge of capacitor212. At the end of the inspection zone during proper operation, thepotential conductor 210 will return to ground level, turning offtransistors 0504-1 and 0505-1 and enabling the charging of capacitor212. The charging circuit for capacitor 212 extends from supply line 214to movable tap 215 of potentiometer P500, and to the upper plate ofcapacitor 212, and from the lower plate of capacitor 212 throughresistor 216 and potentiometer P501 to ground. As the capacitor 212pregressively charges, the potential of the plus input of amplifierRM311B progressively decreases. The extreme right hand conductor 220 inFIG. 8 reads from the error analog output of the error sensing circuitryand is applied to the minus input of amplifier LM311B. Thus, whencapacitor 212 has charged sufficiently so that the potential at theupper input of LM311B matches the error signal at the lower input, andoutput pulse occurs at output line 221 (providing transistor 0504-1 isnonconducting so that conductors 222 and 223 can approach supplypotential. As capacitor 212 continues to charge, transistor 0506 is heldon energizing the selected one of the coils REED 1 or REED 2, and thisresults in turn on of the error correction servo for a time intervalsubstantially linearly proportional to the error count determined by theerror sensing circuitry. The linearity of the digital to analogconverter circuit associated with the error counter is compensated bythe complementary nonlinearity of the capacitor charging circuit forcapacitor 212, so that the resultant on time of the selected REED relaywill be linearly proportional to error count within approximately tenpercent, for example. Potentiometer P500 is adjust able to define theextent of a dead zone" within which small errors will not cause theactuation of the output circuitry. Potentiometer P501 serves as a gainadjustment for the error count of on time circuit.

Referring to the circuitry at the lower left in FIG. 8, monostablecircuit 230 responds to substantial simultaneity at the conductors 231and 199 of switch 191 and supplies a corresponding control signal tooutput'conductor 232 leading to the circuitry of FIG. 9. Conductor 233transmits the information with respect to the scanner phase to thecircuitry of FIG. 9.

FIG. 9

As indicated at the upper left in FIG. 9, a reset signal is receivedfrom conductor 131 of FIG. in response to the Scope Trigger signal. Theresult is that the inspection zone of the sensing circuitry of FIG. 9 issynchronized with the active display cycle of the display apparatus asrepresented in FIG. 1G. Thus, the display apparatus will display thescanner signals which are actually effective within the error sensingcircuitry of FIG. 9. In particular, the reset signal at conductor 131 atthe upper left in FIG. 9 serves to reset the scan gate countercomprising stages 90E, 90F and 906 at the center left of FIG. 9.Similarly, the reset pulse of conductor 133 at the upper left serves toreset'the stages 90A and 90B of the error counter at the beginning ofthe inspection zone, or scan gate interval.

When the leading pulse such as pulse Al shown in FIG. 2 arrives viaconductor 233 at the upper left of FIG. 9, the counter error counterstages 90A and 90B are enabled via conductor 250, and the error counterbegins counting the double rate encoder pulses supplied at input 135.The digital to analog converter 252 serves to supply an analog errorsignal to conductor 220 leading to the output control circuit of FIG. 8previously discussed. The error count is also supplied to component 47ABat the lower right in FIG. 9 and to transducer 254 so as to produce thedigital error display in accordance with the registered error count.Transistor 255 of the display 54 is controlled from conductor 201leading from the polarity sensing bistable 200 of FIG. 8. Thus, thecorrect polarity (plus or minus) is displayed in accordance with thetime of arrival of the pulses at conductors 199 and 231 in FIG. 8.

If the error sensing circuitry is operating properly and the secondscanner signal arrives within the inspection zone, the output of gate20-1 will supply a ground potential to conductor 210 at the end of theinspection zone, enabling the output circuit of FIG. 8 as previouslydescribed.

FIGS. 10 and 10A FIGS. 10 and 10A on sheet 5 of the drawings illustratethe output drive circuit which is indicated as being controlled by therelays REED 1, REED 2 and REED 3 of FIG. 8. Component 270 in FIG. 10represents any suitable bidirectional output servo which may respond toalternating current energization applied between supply lines 271 and272. With the energization of reed coil REED 1, alternating currentpotential may be supplied to conductor 274 in FIG. 10, while with theenergization or reed relay coil REED 2, alternating current potentialmay be supplied to conductor 275.

FIG. 10A illustrates an exemplary embodiment of bidirectional outputservo 270 comprising a pair of rectifiers 281 and 282 controlling thepolarity of energization of the armature winding of a direct currentmotor 283 having a permanent magnet field. The output of the motor asindicated by dash line 284 may be coupled to a web compensating device285 so as to actuate the device in a direction tending to return the webto the desired longitudinal registration condition at the work station Bindicated in FIG. 1.

Summary of Operation Thus, with the illustrated embodiment, an analogadjustment knob 40 shown at the upper center at FIG. 1 and at the leftcenter of FIG. 5 is continuously adjustable, for example, through tenturns, to continuously vary the portion of a repeat length of the webwhich is displayed by means of the display apparatus 60. The portiondisplayed is advantageously keyed to the inspection zone or scanner gateinterval defined by the sensing circuitry 50 shown at the lower right inFIG. 1. This inspection zone is defined by the count capacity of thescan gate counter stages 90E, 90F and 906 at the center left in FIG. 9.Where the scan gate interval corresponds to 500 encoder pulses, gate 76shown at the center right of FIG. 1, may be coupled with the horizontaldeflection counter to terminate a display cycle at a corresponding countof encoder pulses. In the specific circuitry indicated, the scan gatecounter counts double rate encoder pulses, and the deflection counter ofcomponent indicated at the lower right in FIG. 3 is set to trigger gate76 at a count of 248 (corresponding to 496 double rate encoder pulses).Thus, the display indicated in FIG. 2 would actually represent 496double encoder pulses, but would still essentially correspond to theextent of the inspection zone or scan gate interval of the registrationerror sensing circuitry of component 50 shown at the lower right in FIG.1.

Of course, if switch 72 shown in the center of FIG. 1 is shited to thelower portion, then the encoder pulse rate may be divided be a factorsuch as 20 prior to being supplied to the horizontal deflection counterof component 70, and gate 76 may not terminate a display cycle unit] acount of 9,920 encoder pulses (corresponding to 19,840 double rateencoder pulses).

With the aid of the display apparatus 60, the control 40 may bemanipulated until stable scanner pulses appear on the display asrepresented in FIG. 2. Since the display apparatus is locked to webmovement, stable scanner pulses occurring in response to uniform marksin the successive repeat lengths of the web will be readily apparent,while unstable marks can be avoided and spurious markings are readilyexcluded from the inspection zone.

It should be noted that the control knob 40 is convenient and economicalmethod of adjusting the phase of the inspection zone with respect to arepeat length on the web, irrespective of whether the control alsoeffects a corresponding adjustment with respect to an inspection zonedisplay.

While a cathode tube is a convenient type of display and relativelyeconomical at the present time, it will be understood that other typesof displays having acyclical reference displacement axis and a displaysignal axis can be readily substituted for the particular deviceillustrated herein by way of example.

It will be apparent that many further modifications and variations maybe effected without departing from the scope of the novel concepts ofthe present invention.

We claim as our invention:

' 1. A display system for use with equipment involving coordinatedmechanical movements during the operation thereof, comprising,

an encoder for coupling with mechanical movement in the equipment andoperable for generating encoder pulses as a function of successiveuniform increments of the mechanical movement coupled thereto,

display apparatus having a visual display and having a first scanningcontrol input for producing scanning along a first coordinate axis insuccessive scanning cycles of the display and having a second scanningcontrol input for producing display of input signals with respect to asecond coordinate axis of the display,

a cyclically operable deflection counter converter connected with saidencoder and operable for cyclically generating a first deflection signalas a function of the mechanical movement coupled to the encoder, andconnected with said first scanning control input of said displayapparatus and operable in response to an actuating signal for supplyingsaid first deflection signal thereto to control a scanning cycle of saiddisplay apparatus,

input signal means responsive to mechanical movement to be coordinatedwith the mechanical movement coupled to said encoder to producecyclically occurring input signals and connected with said secondscanning control input to supply said input signals thereto,

a cyclically operable ramp generator connected with said encoder andresponsive to successive encoder pulses from said encoder to produce aramp output incrementally changing in amplitude over a given amplituderange in each cycle of operation, and

an amplitude selector progressively adjustable to any selected amplitudesetting corresponding to any of the amplitudes of said ramp outputwithin said amplitude range and operable to generate an actuating signalin each cycle of operation of the ramp generator when the amplitude ofthe ramp output reaches the selected amplitude setting, and connectedwith said deflection counter converter to supply said actuating signalthereto and thus to initiate the successive scanning cycles of saiddisplay apparatus in accordance with the selected amplitude setting ofsaid amplitude selector.

2. A display system in accordance with claim 1 with said ramp generatorhaving a cycle of operation corresponding to a predetermined number ofencoder pulses representing mechanical movement corresponding to arepeat length of a moving material being acted upon by the equipment,and

said deflection counter converter being operable to produce fulldeflection of the display apparatus in response to a lesser number ofencoder pulses 6 which lesser number is only a fraction of saidpredetermined number of encoder pulses, thereby to enable fulldeflection visual display on input signals with respect to any selectedportion of successive repeat lengths of the moving material.

3. A display system in accordance with claim 2 with a pulse rate dividerselectively connectable in circuit between said encoder and saiddeflection counter converter to provide for full deflection of saiddisplay apparatus in response to said predetermined number of encoderpulses, thereby to selectively visually display input signals occurringwith respect to substantially a complete repeat length of the movingmaterial.

4. A display system in accordance with claim 1 with said counterconverter having a bistable display control coupled to said amplitudeselector for actuation by said actuating signal to an active conditionto initiate a cycle of operation of said counter converter and foractuation to an inactive condition when the counter converter hascompleted its cycle of operation, said input signal means having a pairof controllable input signal circuits for selectively transmittingrespective input signals to the second scanning control input of saiddisplay apparatus, an da toggle circuit connected with said bistabledisplay control for actuation to alternate states in alternate cycles ofsaid counter converter, and controlling said input signal circuits toprovide for the alternate activation of said pair of input signalcircuits and thereby to enable the super position at said visual displayof the respective input signals transmitted by the respective inputsignal circuits.

5. A display system in accordance with claim 1 with respective amplitudeselectors for association with respective stations along a path ofmovement through the equipment, and selector switches for selectivelyconnecting the respective amplitude selectors in circuit with said rampgenerator and said first scanning control input, and for simultaneouslysupplying input signals from the respective corresponding stations tosaid second scanning control input.

6. In a register error sensing system for sensing errors in registerbetween successive repeat lengths of a mov ing web and successive workstations operatively disposed along the path of the web, said systemcomprisan encoder responsive to web movement and operable for generatingencoder pulses as a function of successive uniform increments of suchmovement,

an index generator operable to issue an index pulse each time the webmoves a distance corresponding to a repeat length thereof and thereby todefine successive cycles of operation relative to said web movement,

register error sensing circuitry responsive to an initiating signal insaid successive cycles of operation to define a set point representing aregistration condition between the web and one of said stations andoperable in response to a scanner signal from such station to generatean error signal as a function of any departure from the desired registercondition as defined by said set point,

a cyclically operable pulse responsive generator connected with saidencoder and with said index generator and responsive to the successiveindex pulses to initiate successive generating cycles, and operable inresponse to said encoder pulses in each generating cycle to generate ananalog signal successively changing in an analog characteristic thereofover a given range of analog values, and

an analog selector circuit progressively adjustable to any selectedanalog setting corresponding to any of the analog values of said analogcharacteristic within said given range and responsive to a matchingrelationship in said analog characteristic between said successivelychanging analog signal and said selected analog setting of said selectorcircuit for generating said initiating signal and connected

1. A display system for use with equipment involving coordinated mechanical movements during the operation thereof, comprising, an encoder for coupling with mechanical movement in the equipment and operable for generating encoder pulses as a function of successive uniform increments of the mechanical movement coupled thereto, display apparatus having a visual display and having a first scanning control input for producing scanning along a first coordinate axis in successive scanning cycles of the display and having a second scanning control input for producing displAy of input signals with respect to a second coordinate axis of the display, a cyclically operable deflection counter converter connected with said encoder and operable for cyclically generating a first deflection signal as a function of the mechanical movement coupled to the encoder, and connected with said first scanning control input of said display apparatus and operable in response to an actuating signal for supplying said first deflection signal thereto to control a scanning cycle of said display apparatus, input signal means responsive to mechanical movement to be coordinated with the mechanical movement coupled to said encoder to produce cyclically occurring input signals and connected with said second scanning control input to supply said input signals thereto, a cyclically operable ramp generator connected with said encoder and responsive to successive encoder pulses from said encoder to produce a ramp output incrementally changing in amplitude over a given amplitude range in each cycle of operation, and an amplitude selector progressively adjustable to any selected amplitude setting corresponding to any of the amplitudes of said ramp output within said amplitude range and operable to generate an actuating signal in each cycle of operation of the ramp generator when the amplitude of the ramp output reaches the selected amplitude setting, and connected with said deflection counter converter to supply said actuating signal thereto and thus to initiate the successive scanning cycles of said display apparatus in accordance with the selected amplitude setting of said amplitude selector.
 2. A display system in accordance with claim 1 with said ramp generator having a cycle of operation corresponding to a predetermined number of encoder pulses representing mechanical movement corresponding to a repeat length of a moving material being acted upon by the equipment, and said deflection counter converter being operable to produce full deflection of the display apparatus in response to a lesser number of encoder pulses which lesser number is only a fraction of said predetermined number of encoder pulses, thereby to enable full deflection visual display on input signals with respect to any selected portion of successive repeat lengths of the moving material.
 3. A display system in accordance with claim 2 with a pulse rate divider selectively connectable in circuit between said encoder and said deflection counter converter to provide for full deflection of said display apparatus in response to said predetermined number of encoder pulses, thereby to selectively visually display input signals occurring with respect to substantially a complete repeat length of the moving material.
 4. A display system in accordance with claim 1 with said counter converter having a bistable display control coupled to said amplitude selector for actuation by said actuating signal to an active condition to initiate a cycle of operation of said counter converter and for actuation to an inactive condition when the counter converter has completed its cycle of operation, said input signal means having a pair of controllable input signal circuits for selectively transmitting respective input signals to the second scanning control input of said display apparatus, and a toggle circuit connected with said bistable display control for actuation to alternate states in alternate cycles of said counter converter, and controlling said input signal circuits to provide for the alternate activation of said pair of input signal circuits and thereby to enable the super position at said visual display of the respective input signals transmitted by the respective input signal circuits.
 5. A display system in accordance with claim 1 with respective amplitude selectors for association with respective stations along a path of movement through the equipment, and selector switches for selectively connecting the respective amplitude selectors in circuit with said ramp generator and said first Scanning control input, and for simultaneously supplying input signals from the respective corresponding stations to said second scanning control input.
 6. In a register error sensing system for sensing errors in register between successive repeat lengths of a moving web and successive work stations operatively disposed along the path of the web, said system comprising: an encoder responsive to web movement and operable for generating encoder pulses as a function of successive uniform increments of such movement, an index generator operable to issue an index pulse each time the web moves a distance corresponding to a repeat length thereof and thereby to define successive cycles of operation relative to said web movement, register error sensing circuitry responsive to an initiating signal in said successive cycles of operation to define a set point representing a registration condition between the web and one of said stations and operable in response to a scanner signal from such station to generate an error signal as a function of any departure from the desired register condition as defined by said set point, a cyclically operable pulse responsive generator connected with said encoder and with said index generator and responsive to the successive index pulses to initiate successive generating cycles, and operable in response to said encoder pulses in each generating cycle to generate an analog signal successively changing in an analog characteristic thereof over a given range of analog values, and an analog selector circuit progressively adjustable to any selected analog setting corresponding to any of the analog values of said analog characteristic within said given range and responsive to a matching relationship in said analog characteristic between said successively changing analog signal and said selected analog setting of said selector circuit for generating said initiating signal and connected with said register error sensing circuitry for supplying said initiating signal thereto, whereby the set point for said register error sensing circuitry is progressively adjustable to establish the desired set point relative to said successive cycles of operation. 